1.7 KiB
1.7 KiB
use and pub
- π We can bring two types of the same name into the same scope with use, but you need
as
keyword.
use std::fmt::Result;
use std::io::Result;
fn main() {}
- ππ If we are using multiple items defined in the same crate or module, then listing each item on its own line will take up too much verticall space.
// FILL in the blank in two ways
// DON'T add new code line
use std::collections::__;
fn main() {
let _c1:HashMap<&str, i32> = HashMap::new();
let mut c2 = BTreeMap::new();
c2.insert(1, "a");
let _c3: HashSet<i32> = HashSet::new();
}
Re-exporting names with pub use
- πππ In our recently created package
hello-package
, add something to make the below code work
fn main() {
assert_eq!(hello_package::hosting::seat_at_table(), "sit down please");
assert_eq!(hello_package::eat_at_restaurant(),"yummy yummy!");
}
pub(in Crate)
Sometimes we want an item only be public to a certain crate, then we can use the pub(in Crate)
syntax.
Example
pub mod a {
pub const I: i32 = 3;
fn semisecret(x: i32) -> i32 {
use self::b::c::J;
x + J
}
pub fn bar(z: i32) -> i32 {
semisecret(I) * z
}
pub fn foo(y: i32) -> i32 {
semisecret(I) + y
}
mod b {
pub(in crate::a) mod c {
pub(in crate::a) const J: i32 = 4;
}
}
}
Full Code
The full code of hello-package
is here.
You can find the solutions here (under the solutions path), but only use it when you need it :)